About this calculator

UK Building Regs (Part L) recommend 270 mm of mineral-wool loft insulation. A standard roll is 1.14 m wide × 6.0 m long (170 mm) or 5.6 m (200 mm). Lay 100 mm between joists and 170 mm cross-laid to reach 270 mm total.

Frequently asked questions

What does the Loft Insulation Roll Calculator do?

Mineral-wool roll count for loft insulation to UK 270 mm building-regs depth. UK Building Regs (Part L) recommend 270 mm of mineral-wool loft insulation. A standard roll is 1.14 m wide × 6.0 m long (170 mm) or 5.6 m (200 mm). Lay 100 mm between joists and 170 mm cross-laid to reach 270 mm total.

Is the Loft Insulation Roll Calculator free to use?

Yes. Every calculator on Calcurly.com is free, works in your browser without sign-up, and can be embedded on your own website.

How accurate is the Loft Insulation Roll Calculator?

Results are calculated in real time using industry-standard formulas. Treat the output as a well-informed estimate — always cross-check with local regulations, product datasheets, or a qualified insulation professional before committing to a purchase or a job.

What inputs does the Loft Insulation Roll Calculator need?

Enter values for: Loft area (m²), Roll length (m), Roll width (m). Sensible defaults are pre-filled where possible so you can start with a single change.

Can I embed the Loft Insulation Roll Calculator on my own website?

Yes — copy the iframe snippet at the bottom of this page, or use the Embed Generator to customise the size. The embedded version stays in sync with the live calculator on Calcurly.com.